Name of group: GM group Group secretary plus email: Sian Peck (bt09019@qmul.ac.uk) Group members plus email: Sally Faulkner (bt09226@qmul.ac.uk), Jane Hardwick (bt09278@qmul.ac.uk), Chris Hughes (bt09179@qmul.ac.uk), Katie Daughters (bt09117@qmul.ac.uk)
Task, Describe why GMOs may impact the wild, 1000 words maximum, referenced.
Describe Why GMOs May Impact the Wild Genetically modified organisms (GMOs) have undergone genetic engineering in a lab, altering DNA or RNA to produce particular desired traits. GMOs include plants (most commonly crops), animals and micro-organisms (viruses, bacteria and fungi). The discovery of restriction enzymes in 1970 made genetic modification possible as they recognise a sequence of nucleotides and are able to make a staggered cut allowing foreign DNA with a matching cut to be inserted, producing an organism with a new or altered trait (Health and safety executive, 2010). The TI plasmid, mentioned by Campbell (2006), from the soil bacterium Terium tumefaciensis a common vector used to introduce new genes into plant cells. By using retriction enzymes to create recombinant DNA, transgenic organisms can be produced.
As eco-systems are mutli-factorial, it makes the potential impacts of GMO’s difficult to predict. On the other hand due to the very nature of genetic modification it is possible to ascertain some of the risks through experimentation. One of the main concerns around GMOs are if horizontal and vertical gene flow could effect wild species, although in some cases this is impossible, if major crops are not native to the areas in which they are grown they will have no close wild relatives needed for gene flow to occur.
Brassica napus,rapeseed that has been genetically modified using the Roundup Ready gene allowing it to be resistant to herbicide, is able to form crosses with 16 relatives growing within the UK. Hybrids frequently occur between the commercially grown B. rapaand the wildtype B. napus.This wildtype occurs abundantly in waterside populations and less abundantly as an agricultural weed . Wilkinson (2003) estimates that 32,000 hybrids form annually in waterside B. rapa populations, whereas the less abundant weedy populations contain 17,000 hybrids. Potential environmental hazards associated with this hybridization include changes to local ecostructures, enhanced invasiveness and possible local extinction caused by interaction with the transgene recipient although the possibility of any of these factors occurring depends on the species with which the hybridization occurs (Ford et al, 2006). Wilkinson’s study (2003) infers that widespread and frequent hybridization is possible although will not inevitably result in environmental change as potential fitness must be taken into account. Potentially though, riverside hybrids tend to cause complex ecological changes and weedy hybrids principally caused adjustments to agricultural practice.
An example of an indirect but beneficial effect of GMOs is the reduction in the use of hazardous chemicals: insecticides and pesticides. Although clearly beneficial to farmers for increased yield, they could have detrimental effects on the environment and grassland invertebrate population dynamics, not to mention the health of the farm workers themselves.....not clear what you are saying about farmers, contradictory Genetic modification has revealed a solution to this issue by introducing the Bacillus thuringiensis(Bt) gene into crops. Bt is a gram-positive bacterium which produces a ‘Cry’ toxin that kills several orders of insects. When this gene was introduced to several million cotton farmers in China, it reduced their pesticide use by 70%, thus significantly reducing pesticide poisoning among the farmers themselves (Pray and Ma, 2001). The negative effects, however, could be that it creates a selection pressure in these insects to become resistant to the Bt gene. If this occurs, then most of the insect population would once again be able to feed on agricultural plants. Although as of yet there is no evidence of this.....and resistance evolves to all insecticides anyway, over time
There is evidence, however, that acquired resistance to herbicides has occurred in GM/wild plant hybrids. The debate is whether this is really a negative side effect of GM crops. The argument being that the selection pressure created by GM crops on weeds would occur in the wild naturally anyway. The Red Queen hypothesis, states that in order to maintain relative fitness an organism must be continually evolving. Applying this hypothesis to GM crops, when a new GM crop is introduced there is an instant selection pressure in weeds to develop a resistance mutation. But is this really any different to the selection pressure in a natural environment, where weeds are continually evolving against new mutations in plants? Hence this hybrid (a weed with the GMOs resistance gene) would occur with or without the introduction of the GM crop because it is said to be an innate evolutionary process.
It is common practice to modify cotton crops to contain a gene which is resistant to the chemical herbicide, bromoxynil (BXN). Immediate effects of this engineering is an increased yield, as less crops die due to the higher tolerance. However, there is an ongoing debate whether GM crops are actually able to produce higher yields; Charles Benbrook of the Organic Centre has stated that some species of GM plants actually produce lower yields than that of organic plants (Benbrook, 1999). This is true in the case of the Hawaiian Papaya, where the GM crop has stunted growth as a consequence to its GM resistance gene. The gene added prevents the species from contracting papaya ringspot virus, this causes the plant to produces less fruit and for the plant itself to become stunted.
GMO’s present a subtle ecological balance, which, if to be successfully integrated into modern day farming, must be carefully managed. All farming will affect the environment, be it subsistence, organic or intensive and there is still much discussion as to whether GMO’s will indirectly contribute to this beneficially or detrimentally. Transgenic crops could, and in some cases have, entered the wild via gene flow, passing on undesirable traits in natural habitats. There is also potential for the local biodiversity to indirectly receive impact with varying effectiveness of insecticides, allowing species of pests into the natural environment with acquired resistance. The main consideration is whether the use of GMO’s can improve the current indirect impacts that farming has on the ecological systems that surround it and how much evidence and research is needed on both accounts to ultimately accept or reject the innovation of GMO’s in modern day agriculture.
Bendrook. C. M. 1999. Evidence of the Magnitude and Consequences of the Roundup Ready Soybean Yield Drag from University Based Varietal Trials in 1998. Ag Biotech InfoNet Technical Paper. [online]. Available at: __(http://www.biotech-info.net/RR_yield_drag_98.pd)__ > [Accessed 11 October 2010]
Campbell, M., Reece, J.B., Taylor, M.R., Simon, E.J. 2006. Biology: Concepts and connections. Fifth edition. San Fransico, CA: Pearson Benjamin Cummings.
Ford et al., 2006. Spontaneous gene flow from rapeseed (Brassica napus) to wild Brassica oleracea. Proc. R. Soc. B273, 3111–3115
Pray, C., and Ma, D., 2001. Impact of Bt cotton in China. World development.29(5) pp 813-825
Wilkinson et al,. 2003. Hybridization Between Brassica napus and B. rapa on a National Scale in the United Kingdom. Science Express. 302. pp. 457 - 459
Group secretary plus email: Sian Peck (bt09019@qmul.ac.uk)
Group members plus email: Sally Faulkner (bt09226@qmul.ac.uk), Jane Hardwick (bt09278@qmul.ac.uk), Chris Hughes (bt09179@qmul.ac.uk), Katie Daughters (bt09117@qmul.ac.uk)
Task, Describe why GMOs may impact the wild, 1000 words maximum, referenced.
Describe Why GMOs May Impact the Wild
Genetically modified organisms (GMOs) have undergone genetic engineering in a lab, altering DNA or RNA to produce particular desired traits. GMOs include plants (most commonly crops), animals and micro-organisms (viruses, bacteria and fungi). The discovery of restriction enzymes in 1970 made genetic modification possible as they recognise a sequence of nucleotides and are able to make a staggered cut allowing foreign DNA with a matching cut to be inserted, producing an organism with a new or altered trait (Health and safety executive, 2010). The TI plasmid, mentioned by Campbell (2006), from the soil bacterium Terium tumefaciens is a common vector used to introduce new genes into plant cells. By using retriction enzymes to create recombinant DNA, transgenic organisms can be produced.
As eco-systems are mutli-factorial, it makes the potential impacts of GMO’s difficult to predict. On the other hand due to the very nature of genetic modification it is possible to ascertain some of the risks through experimentation. One of the main concerns around GMOs are if horizontal and vertical gene flow could effect wild species, although in some cases this is impossible, if major crops are not native to the areas in which they are grown they will have no close wild relatives needed for gene flow to occur.
Brassica napus, rapeseed that has been genetically modified using the Roundup Ready gene allowing it to be resistant to herbicide, is able to form crosses with 16 relatives growing within the UK. Hybrids frequently occur between the commercially grown B. rapa and the wildtype B. napus.This wildtype occurs abundantly in waterside populations and less abundantly as an agricultural weed . Wilkinson (2003) estimates that 32,000 hybrids form annually in waterside B. rapa populations, whereas the less abundant weedy populations contain 17,000 hybrids. Potential environmental hazards associated with this hybridization include changes to local ecostructures, enhanced invasiveness and possible local extinction caused by interaction with the transgene recipient although the possibility of any of these factors occurring depends on the species with which the hybridization occurs (Ford et al, 2006). Wilkinson’s study (2003) infers that widespread and frequent hybridization is possible although will not inevitably result in environmental change as potential fitness must be taken into account. Potentially though, riverside hybrids tend to cause complex ecological changes and weedy hybrids principally caused adjustments to agricultural practice.
An example of an indirect but beneficial effect of GMOs is the reduction in the use of hazardous chemicals: insecticides and pesticides. Although clearly beneficial to farmers for increased yield, they could have detrimental effects on the environment and grassland invertebrate population dynamics, not to mention the health of the farm workers themselves.....not clear what you are saying about farmers, contradictory Genetic modification has revealed a solution to this issue by introducing the Bacillus thuringiensis (Bt) gene into crops. Bt is a gram-positive bacterium which produces a ‘Cry’ toxin that kills several orders of insects. When this gene was introduced to several million cotton farmers in China, it reduced their pesticide use by 70%, thus significantly reducing pesticide poisoning among the farmers themselves (Pray and Ma, 2001). The negative effects, however, could be that it creates a selection pressure in these insects to become resistant to the Bt gene. If this occurs, then most of the insect population would once again be able to feed on agricultural plants. Although as of yet there is no evidence of this.....and resistance evolves to all insecticides anyway, over time
There is evidence, however, that acquired resistance to herbicides has occurred in GM/wild plant hybrids. The debate is whether this is really a negative side effect of GM crops. The argument being that the selection pressure created by GM crops on weeds would occur in the wild naturally anyway. The Red Queen hypothesis, states that in order to maintain relative fitness an organism must be continually evolving. Applying this hypothesis to GM crops, when a new GM crop is introduced there is an instant selection pressure in weeds to develop a resistance mutation. But is this really any different to the selection pressure in a natural environment, where weeds are continually evolving against new mutations in plants? Hence this hybrid (a weed with the GMOs resistance gene) would occur with or without the introduction of the GM crop because it is said to be an innate evolutionary process.
It is common practice to modify cotton crops to contain a gene which is resistant to the chemical herbicide, bromoxynil (BXN). Immediate effects of this engineering is an increased yield, as less crops die due to the higher tolerance. However, there is an ongoing debate whether GM crops are actually able to produce higher yields; Charles Benbrook of the Organic Centre has stated that some species of GM plants actually produce lower yields than that of organic plants (Benbrook, 1999). This is true in the case of the Hawaiian Papaya, where the GM crop has stunted growth as a consequence to its GM resistance gene. The gene added prevents the species from contracting papaya ringspot virus, this causes the plant to produces less fruit and for the plant itself to become stunted.
GMO’s present a subtle ecological balance, which, if to be successfully integrated into modern day farming, must be carefully managed. All farming will affect the environment, be it subsistence, organic or intensive and there is still much discussion as to whether GMO’s will indirectly contribute to this beneficially or detrimentally. Transgenic crops could, and in some cases have, entered the wild via gene flow, passing on undesirable traits in natural habitats. There is also potential for the local biodiversity to indirectly receive impact with varying effectiveness of insecticides, allowing species of pests into the natural environment with acquired resistance. The main consideration is whether the use of GMO’s can improve the current indirect impacts that farming has on the ecological systems that surround it and how much evidence and research is needed on both accounts to ultimately accept or reject the innovation of GMO’s in modern day agriculture.
Bendrook. C. M. 1999. Evidence of the Magnitude and Consequences of the Roundup Ready Soybean Yield Drag from University Based Varietal Trials in 1998. Ag Biotech InfoNet Technical Paper. [online]. Available at: __(http://www.biotech-info.net/RR_yield_drag_98.pd)__ > [Accessed 11 October 2010]
Campbell, M., Reece, J.B., Taylor, M.R., Simon, E.J. 2006. Biology: Concepts and connections. Fifth edition. San Fransico, CA: Pearson Benjamin Cummings.
Ford et al., 2006. Spontaneous gene flow from rapeseed (Brassica napus) to wild Brassica oleracea. Proc. R. Soc. B 273, 3111–3115
Heath and Safety Executive, 2010. //About Genetically Modified Organisms.[online] Available at: <//__http://www.hse.gov.uk/biosafety/gmo/about.htm>__
Pray, C., and Ma, D., 2001. Impact of Bt cotton in China. World development. 29(5) pp 813-825
Wilkinson et al,. 2003. Hybridization Between Brassica napus and B. rapa on a National Scale in the United Kingdom. Science Express. 302. pp. 457 - 459